The preparation of electronic devices such as field effect transistor (FET) devices, light emitting devices (LED) and photovoltaic (PV) devices usually comprises the application and structuring, also called patterning, of various layers such as the application and structuring of the electrodes, as well as, the application and structuring of the semiconducting layer, the dielectric layer and of other layers such as barrier layers.
The electrode material is usually applied by evaporation followed by structuring of the electrode material layer using photolithography, which involves the application of a photoresist-layer, exposure of the photoresist-layer to radiation using a mask, removal of the photo-resist not-exposed to radiation, etching of the exposed electrode material, and removal of the remaining photo-resist.
The most convenient way to apply the semiconducting layer, the dielectric layer and other layers such as barrier layers is by solution processing techniques such as spin coating or printing. When using liquid processing techniques it is important that the solution of the layer to be applied does not dissolve the layer already present in the device. Thus, one needs to either use solvents that do not dissolve the layer already present, so-called orthogonal solvents, or render the layer already present in the device insoluble or less soluble towards the solvent of the next layer to be applied. One way to render a polymer layer insoluble or less soluble towards the solvent of the next layer to be applied is by cross-linking this polymer layer. Depending on the cross-linkers used, the crosslinking can be initiated by thermal treatment or by radiation treatment. Radiation treatment has the advantage compared to thermal treatment that by using a mask only part of the polymer layer are cross-linked so that the cross-linking and the structuring step can be combined in one step. The not cross-linked polymer can be easily removed by washing with a suitable solvent, whereas structuring of a polymer layer cross-linked by thermal treatment is usually performed using photolithography, which involves a serious of steps as outlined above for the application and structuring of the electrodes.
Bis-azide-type compounds are cross-linkers that can be activated by radiation treatment. Several bis-azide-type compounds and their application in the preparation of electronic devices have already been described.
Cai, S. X.; Glenn, D. J.; Kanskar, M.; Wybourne, M. N.; Keana, J. F. W. Chem. Mater 1994, 6, 1822-1829 describes the following bis-azide-type compounds

Polystyrene mixtures containing the cross-linkers above were evaluated as deep-UV and electron beam resists.
Yan, M.; Cai, S. X.; Wybourne, M. N.; Keana, J. F. W. J. Mater. Chem. 1996, 6, 1249-1252 describes the following bis-azide-type compounds

Polyimide mixtures containing the cross-linkers above were evaluated as negative resists.
Touwslager, F. J.; Willard, N. P.; Leeuw, D. M. Applied Physics Letters 2002, 81, 4556 describes a lithography process for forming a layer from poly(3,4-ethylenedioxythiophene) (PEDOT). The fully water-borne process is based on photocross-linking PEDOT using the following bis-azide-type compound

The technology has been applied to fabricate an all-polymer field-effect transistor and integrated circuit.
WO 04/100282 describes a method of forming a polymer device including the steps of (i) depositing on a substrate a solution comprising a polymer or oligomer and a crosslinking moiety to form a layer, (ii) curing the layer formed in step (i) under conditions to form an insoluble cross-linked polymer, characterized in that the crosslinking moiety is present in step (i) in an amount in the range of 0.05 to 5 mol % based on the total number of moles of repeat units of the polymer or oligomer and the crosslinking moiety in the solution. Polymer devices include field-effect transistors. It is preferred that the crosslinking moiety has an absorption in the narrow transmission window in the deep ultraviolet. Typically, this will be in the range 200 to 300 nm. WO 04/100282 exemplifies the following cross-linking moieties:

WO 2007/004995 describes a class of cross-linking compound, said compound comprising (i) one or more fluorinated aromatic group and (ii) one or more ionisable group, wherein the cross-linking compound is soluble in at least one polar solvent. The general formula of this class of cross-linking compound is given by formula N3—ArFZ(R)—N3 (I), wherein ArFZ comprises one or more fluorinated aromatic groups, and R comprises one or more ionisable group, wherein the cross-linking compound is soluble in at least one polar solvent. WO 20071004995 also describes a process of forming a device comprising a polymer is provided, the process includes the steps of (i) depositing a film from a solution comprising a polymer and the crosslinking compound on a substrate and (ii) soft-baking the film at a temperature between 100 to 130° C.; and (iii) exposing the solution in step (ii) to radiation having a wavelength in a range of 250 to 450 nm. Exemplified is the cross-linking compound of formula
wherein X is selected from I, PF6, BF4, ClO4 and CF3COO,
WO 2009/068884 describes a supported polymer heterostructure and methods of manufacture. The heterostructure is suitable for use in a range of applications which require semiconductor devices including photovoltaic devices and light-emitting diode devices. For example, a process is described which comprises the steps of preparing a solution of poly(9,9′-dioctylfluorene-co-bis-N,N′-(4-butylphenyl)-bis-N,N-phenyl-1,4-phenylene diamine), polystyrene and the following bis-azide-type photocross-linker

in toluene, spincoating this solution on a support, removing polystyrene by methyl ethyl ketone treatment, and exposing the remaining sample to UV light (254 nm).
Png, R.-Q.; Chia, P.-J.; Tang, J.-C.; Liu, B.; Sivaramakrishnan S.; Zhou, M.; Khong, S.-H.; Chan, H. S. O.; Burroughes, J. H.; Chua, L.-L.; Friend, R. H.; Ho, P. K. H. Nature Materials 2010, 9(2), 152-152 describes that sterically hindered bis(fluorophenyl azides) can be mixed generally into polymer organic semiconductors to cause photocross-linking when exposed to deep-ultraviolet light (254 nm wavelength). An example of a sterically hindered bi(fluorophenyl azide is

For example, a preparation of an OFET is described which comprises the step of photocross-linking poly 2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene) films on an octadecyltrichlorosilylated thermal oxide gate dielectric with p++-Si back gate and lithographically patterned AU source-drain electrodes.
WO 2011/068482 describes the cross-linking moiety having a general formula N3—ArF—W (I), wherein ArF comprises a fluorinated phenyl azide group having at least one non-fluorine substituent that is bulkier than fluorine at a meta position relative to the azide group, and W comprises an electron withdrawing group. WO 2011/068482 also describes a solution comprising the cross-linking moiety, and optionally a polymer or oligomer. WO 2011/068482 also describes a method for forming a polymer device comprising the steps of (a) depositing a solution comprising a polymer or oligomer and a cross-linking moiety on a substrate to form a layer, and (b) curing the layer to form an insoluble cross-linked polymer. The device may be a polymer FET device. For example, example 3 of WO 2011/068482 describes the following cross-linking moiety

The bis-azide-type compounds described in the literature citations above usually absorb at a wavelength of 254 nm.